/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package org.apache.iotdb.db.localconfignode;

import org.apache.iotdb.commons.consensus.ConsensusGroupId;
import org.apache.iotdb.commons.consensus.DataRegionId;
import org.apache.iotdb.commons.path.PartialPath;
import org.apache.iotdb.commons.utils.TestOnly;
import org.apache.iotdb.db.conf.IoTDBDescriptor;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.Arrays;
import java.util.Comparator;
import java.util.List;
import java.util.concurrent.atomic.AtomicInteger;

@Deprecated
public class LocalDataPartitionTable {
    private static final Logger LOG = LoggerFactory.getLogger(LocalDataPartitionTable.class);

    private String storageGroupName;
    private final int regionNum;
    private DataRegionId[] regionIds;

    public LocalDataPartitionTable(String storageGroupName, List<DataRegionId> regions) {
        this.storageGroupName = storageGroupName;
        this.regionNum = regions.size();
        regions.sort(Comparator.comparingInt(ConsensusGroupId::getId));
        this.regionIds = new DataRegionId[regions.size()];
        for (int i = 0; i < regions.size(); ++i) {
            regionIds[i] = regions.get(i);
            DataRegionIdGenerator.getInstance().setIfGreater(regionIds[i].getId());
        }
    }

    public LocalDataPartitionTable(String storageGroupName) {
        this.storageGroupName = storageGroupName;
        this.regionNum = IoTDBDescriptor.getInstance().getConfig().getDataRegionNum();
        this.regionIds = new DataRegionId[regionNum];
    }

    /**
     * Get the data region id which the path located in.
     *
     * @param path The full path for the series.
     * @return The region id for the path.
     */
    public DataRegionId getDataRegionId(PartialPath path) {
        int idx = Math.abs(path.hashCode() % regionNum);
        return regionIds[idx];
    }

    /**
     * Get all data region id of current database
     *
     * @return data region id in list
     */
    public List<DataRegionId> getAllDataRegionId() {
        return Arrays.asList(regionIds);
    }

    public synchronized DataRegionId getDataRegionWithAutoExtension(PartialPath path) {
        int idx = Math.abs(path.hashCode() % regionNum);
        if (regionIds[idx] == null) {
            int nextId = DataRegionIdGenerator.getInstance().getNextId();
            regionIds[idx] = new DataRegionId(nextId);
        }
        return regionIds[idx];
    }

    public void clear() {
        // TODO: clear the table
        regionIds = null;
    }

    public static class DataRegionIdGenerator {
        private static final DataRegionIdGenerator INSTANCE = new DataRegionIdGenerator();
        private final AtomicInteger idCounter = new AtomicInteger(0);

        public static DataRegionIdGenerator getInstance() {
            return INSTANCE;
        }

        public void setCurrentId(int id) {
            idCounter.set(id);
        }

        public int getNextId() {
            return idCounter.getAndIncrement();
        }

        /**
         * Update the id counter when recovering, make sure that after all data regions is recovered,
         * the id counter is greater than any existed region id
         */
        public void setIfGreater(int id) {
            int originVal = idCounter.get();
            while (originVal <= id && !idCounter.compareAndSet(originVal, id + 1)) {
                originVal = idCounter.get();
            }
        }

        @TestOnly
        public void reset() {
            this.idCounter.set(0);
        }
    }
}
